Ok, so you've (hopefully) bought David Allen's book on getting organized. You now (gasp) file things instead of cluttering your desk so you can't find anything. You have an inbox, and you compulsively empty it every day. You're doing your daily/weekly/monthly reviews.
You immediately start running into problems. If you use paper, you're constantly re-copying information around. If you use your computer, when you're out and about, you don't have access to your computer. If you use a Palm/Treo/iPhone, you're limited in what you can do at any moment.
Which is why I started writing Frictionless because:
1. I wanted to be able to easily keep a log of things I do.
2. I wanted to work with both my physical inbox and my electronic inbox (Mail) more easily.
3. I wanted to work with other programs, websites, etc.
4. I wanted to be able to print everything onto 3x5 cards for my wallet because carrying my computer over my shoulder wasn't very comfortable.
5. I wanted it to work seamlessly with the iPhone when it came out.
In essence, I realized that I needed something to act as a digital hub to my GTD system. It had to accept inputs from everything, and export to everything.
Tall order, which is why Frictionless is still in the development stage.